1. Field of the Invention
The present invention is directed to novel bismorpholine derivatives, a process for their production and their use as hydrolysis inhibitors in polymers containing ester and/or carbonate groups.
2. Description of the Prior Art
It is well known that ester groups (including carbonate groups) may undergo hydrolytic decomposition to revert to the starting components. In the case of relatively high molecular weight substances prepared from components containing ester groups, such a reaction causes degradation of the polymer chain which generally results in a loss of mechanical properties. A further disadvantage is the autocatalytic destruction by the continuous formation of new carboxylic acid groups which becomes progressively more drastic.
The reaction of polyesters with isocyanates which are at least bifunctional results in polyurethanes which are widely used industrially as high quality elastomers. In order to protect the superior quality of these polymers against degradation by moist heat, water or steam, it has long been customary to use hydrolysis protective agents such as the group of substances known as carbodiimides which are described in DE-PS 1,005,726 and in BE-PS 610,969, 612,040 and 733,573. FR-PS 1,450,919 discloses iminooxazolidines corresponding to the formula ##STR2## wherein R.sub.1 =aryl,
R.sub.2 =aryl, alkyl PA0 R.sub.3, R.sub.4, R.sub.5 and R.sub.6 represent hydrogen, alkyl, alkenyl, cycloalkyl and/or aryl substituents, preferably C.sub.1 -C.sub.7 -alkyl substituents, or a cycloalkylene or arylene substituent formed by linkage of R.sub.3 and R.sub.6 with aminoethanol, R.sub.4 and R.sub.5 being omitted in the case of arylene substituents. PA0 (a) glyoxal and PA0 (b) N-monosubstituted aminoethanols of the type ##STR4## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 have the meaning described above, R.sub.4 and R.sub.5 being omitted in the case of arylene groups,
as age protective agents for compounds containing ester groups. In both cases, however, the tendency to migration, the deleterious effects on the compression set and the catalytic effects (change in the casting and pot life of polyurethanes) are found to be disadvantageous.
Although the hydroxyalkylurea derivatives described in DE-PS 2,106,726 are found to be quite effective, the high melting points and low solubilities of compounds of this type in polyesters or short chain chain lengthening agents are found to be disadvantageous.
It is an object of the present invention to provide hydrolysis protective agents which do not suffer from the previously discussed disadvantages.
A group of hydrolysis protective agents which have no connection with previously known classes of compounds as regards the course of the reactions and the structure and material properties of the reaction products has now been found completely unexpectedly and must be given a decidedly positive assessment as regards their processing characteristics. These compounds, which have not hitherto been described and which act as hydrolysis protective agents (HSM), are reaction products of glyoxal and aminoethanols substituted with organic groups. The products are cycloacetals as hereinafter described.